Apparatus for preforming clay charges prior to jiggering



May 2, 1950 w. J. MILLER 2,506,375

APPARATUS FOR PREFORMING CLAY CHARGES PRIOR TO JIGGERING Original Filed June 13, 1942 2 Sheets-Sheet 1 PPFPPFFPPP mW L91 3 Q 0 5/1 I 3' Z66 INVENTOR lllfl H T I. MW/ 'am J/VrZ/Z k 505 BY May 2, 1950 2,506,376

W. J. MILLER APPARATUS FOR PREFORMING CLAY CHARGES PRIOR TO JIGGERING Original Filed June 13, 1942 v 2 Sheets-Sheet 2 I- 0k 150 U 0 =E Q B: III

INVENTOR ATTO IE Patented May 2, 1950 APPARATUS FOR PREFORMING CLAY CHARGES PRIOR TO JIGGERING William J. Miller, Swissvale, Pa., assignor to Miller Pottery Engineering Company, Swissvale, Pa., a corporation of Pennsylvania Original application June 13, 1942, Serial No.

446,868. Divided and this application November 3, 1943, Serial No. 509,010

10 Claims.

This is a division of my co-pending application Serial No. 446,868, filed June 13, 1942, now Patent No. 2,499,602. It has to do particularly with the structure for preforming clay charges prior to jiggering in the manufacture of pottery dinnerware and relates to certain improvements in apparatus for rendering the molding implement or implements non-adhesive to clay.

In the drawings, Figure 1 is a sectional elevation showing the preforming station of an automatic jiggering machine.

Figure 2 is a plan view of the preforming station.

Figure 3 is a detail in section of the forming die and support therefor.

Figure 4 is a piping diagram of the gas control apparatus for the press die burner.

Figure 5 is a diagrammatic detail of a modified form of gas control apparatus.

Figure 6 is a wiring diagram of the ignition system.

Figure '7 is a fragmentary plan view of a gas control valve and operating means therefor.

Figure 8 is a side elevation of the apparatus of Figure 7.

Figure 9 is a plan view of the releasable lock for detachably securing ware forming dies in working position.

The dies 239 are mounted for quick exchange on the under sides of open sided box-like brackets 262 mounted on the under side of a hollow supporting lintle 263 secured at its ends upon upper wall extensions 2154 of the housing structures 246 and 241 (Fig. 2). Each die is adjustably threaded onto the stud portion 265 of a base 266 and held locked thereon by a set screw 261 (Fig. 3). The die base 266 is detachably secured to bracket 262 by a quick action latch look. For this purpose, said base has a central tapered boss 269 centered in an aperture 210 in the bracket bottom with a cone headed stem 213 adjustably threaded into the boss and extending through the aperture and a slot 214 in a pivoted latch member 215, with the stem head 216 engaging the inclined upper surface 211 of the latch which acts as a wedging key between the stem head 215 and the bracket bottom to clamp the base on the bracket in the locking position of the latch. To release the die from the bracket, the latch 215 is moved counterclockwise (Fig. 3) to bring the enlarged end 218, Figure 9 of the slot 214 in register with head'ZIE to permit same to pass therethrough. The extended end 219 of the latch enables striking it with a hammer to release and engage the latch, and a spring 280 prevents same from working loose and to take up expansion in stem 213 as it heats up.

To insure that the molds are released from the dies as they are lowered after the pressing operation, especially those for hollow ware, means such as that disclosed in co-pending application Serial No. 205,711, now Patent No. 2,379,737, are employed. To this end. each hollow ware die 239, Figs. 1 and 3, is freely disposed within a downwardly spring pressed mold stripper ring 282 which is raised by a hollow ware mold 238 into pressing engagement therewith upon its final upward movement into operating position with the die, whereby the mold will be stabilized in the chuck during the bat forming operation and whereby the mold will be stripped from the die as it is lowered by the chuck. The stripper ring mold contacting surface may be formed of resilient material such as rubber, and may be secured to a centrally open supporting plate 283 slidably supported at its corners upon bolts 284 depending from the die bracket, with coiled springs 285 on the bolts and disposed between the bracket and plate to urge same against stop nuts 286 on the bottom ends of the bolts.

The dies are herein shown as heated so that their forming surfaces will repel the clay bats formed thereby as they recede therefrom and remain in adhering relation with the molds. For this purpose, each die is hollowed out to present a comparatively thin walled shell against whose inner wall are selectively directed jets of flames from a gas burner 289 depending from the die base 266. There may be a multiple of such burners in the die, if desired. Gas is supplied from gas main 290 (Fig. 4) by way of a conduit 2!, branches 292 leading to air mixing chambers 293 and pipes 294 continuing therefrom to the .burners by way of passages 295 and 296 in the die brackets and die bases respectively (Fig. 3). In each branch 292 may be interposed a throttling valve 291 to regulate the flow of gas to the mixing chambers 293.

The gas in the conduit 29! is supplied under practically zero pressure from main 290 through a reducing valve 300, but is drawn into mixing chambers 293 for proper air mixture and impelled therefrom to burners 289 under a higher pressure by air pressure syphon nozzles 30! arranged in the mixing chambers and connected with a source of air under pressure through a conduit 302 and branches 303 thereof (Fig. 4). A throttling valve 304 is interposed in each branch 303 to control the heating of each individual die. In the conduit 302 is a shut-01f valve 305 with a by-pass 306 thereabout controlled by a needle valve 306a to maintain the dies at a minimum temperature when the valve is automatically closed as the machine is stopped.

As a safety measure, an ordinary igniting element, such as a spark plug 3%? (Fig. 3) is interposed in each die chamber, and momentarily energized during each cycle of operation of the machine to insure that ignition of the gas will be maintained, As seen in Fig. 6, the spark plugs 36'! may be energized successively from a low voltage battery 368 or any suitable source through an ordinary ignition system including a distributor 3&9 whose rotating switch arm shaft lift may be driven by a motor or by the cam shaft :66 through a belt and pulley drive ti i.

In the gas line 29! may be shut-off valve 362 operated by a cam 3 !3 on the cam shaft 55%, Fig. 5, to intermittently admit gas to the burners in timed relation with the ignition system while the crosshead 24! is moving, thus maintaining die temperature constant, regardless of variations in machine speed or stoppages. In this method, spark plugs may be energized frequently or per petual'ly, and may or may not be synchronized with the operation of the gas valve 3&2. Also, a pilot burner Bid (Fig. 5) may be substituted for each spark plug and supplied from the gas main 2% by a branch 35% controlled by a reducing valve 315a, and/or a by-pass Bid may be terposed in the line 29! about the valve 3E2 controlled. by a needle valve til to maintain a prodetermined minimum gas supply for the burners to maintain 'a lower but optimum temperature maintenance flame between pressing cycles.

The object of the herein described structure is to heat the clay engaging surface of the several dies 235, Figure l, of an automatic pottery-ware forming machine in order that the moist clay 209, Figure l, in or on the mold 233 will be repolled therefrom, the moisture in the clay being converted to steam incident to retraction of the mold 238 as the mold lifter or chuck "262 is lowered after the pr'eforl'nin operation.

With regard to Figure i, 561 is a valve for ad justing the maximum flow in supply line tee is a regulating valve for adjusting fluid pressure in the pipe line.

Valve 3535 is connected to the main control rod 520 of the machine through lever 529 and link 53%, see Figures 7 and 8, in order that the fiow of gas to the burners may be reduced, when the operation of th machine is discontinued. and

consequently the dies 239 are not functioning. Otherwise, the dies will become overheated and will dry out the clay too rapidly thereby causing the surface of the ware to become crazed.

What I claim is:

l. The combination with a relatively movable mold suppport and die for acting on clay disposed on pottery molds received by said support, of means for rendering the forming surface or the die coming in contact with the clay non-adhesive thereto including, a combustion chamber in the die, a source of supply of combustible fiuid, means for conducting the same therefrom to the combustion chamber, a valve for varying the flow of fluid to the combustion chamber and means for periodically, automatically, actuating said valve in timed relation with the movement of the mold support relative to the die.

2. The combination with a relatively movable mold support and die for acting on clay disposed on molds received by said support, of means for rendering the clay contacting surface of said die non-adhesive to clay including a combustion chamber in said die, a spark plug for igniting combustible fluid in said chamber, means for intermittently energizing the spark plug, and means for operating said spark plug energizing means in timed relation with the movement of the die and mold support.

3. The combination with a potteryware fabricating machine having a control governing the starting and stopping of the machine, of means for preforming plastic clay including a die, a burner for heating the ware forming surface of said die, means for delivering combustible fluid to said burner, a control valve, a connection between the control valve and the machine control whereby, when the machine control is moved to a position for interrupting the operation of the machine, the control valve is closed to interrupt the delivery of combustible fluid to the die, and an igniter associated with the burner.

4. Pressing apparatus for shaping articles of clay comprising, a die member, a support for said die, a mold support member for receiving jigger molds carrying a charge of clay, means for moving one of said members relative to the other to spread clay over the forming surface of the clay, a stripper for stripping the mold from the die incident to separation of the members, a fuel burner carried by said support positioned and arranged to heat the die, a valve for regulating the amount of fuel fed to the burner, a control for the valve means for periodically and automatically operating said valve in timed relation with the operation of said members to increase and decrease the supply of fuel sufficient to cause the same to release from the clay without appreciable crazing of the surface of the clay, and a pilot burner for the burner.

5. Pressing apparatus for shaping articles of clay comprising, a die member, a support for said die, a mold support member for receiving jigger molds carrying a charge of clay, means for moving one of said members relative to the other to spread clay over the forming surface of the mold, a stripper for stripping the mold from the die incident to separation of the members, a fuel burner carried by said support positioned and arranged to heat the die, a valve for regulating the amount of fuel fed to the burner, a control for the valve means for periodically and automatically operating said valve in timed relation with the operation of said members to increase and decrease the supply of fuel fed to the burner to maintain an operating temperature on the die sufiicient to cause the same to release from the clay without appreciable crazing of the surface of the clay, an electrically operated igniter for the burner, and a periodically, automatically operated means for periodically energizing the i'gniter during the operation of the apparatus.

6. Pressing apparatus for shaping articles of clay comprising, a plurality of die members, a support member for receiving molds carrying a charge of clay, means for moving the die members and support member relative to one another to spread clay over the molding surface of the molds, means for stripping the molds from the dies, a fuel burner associated with each die, a fuel supply line common to all of the burners, a valve for varying the flow of fuel through the line to the several burners, periodically, automatically operated means for actuating the valve to increase and decrease the supply of fuel fed to all of the burners to maintain an operating temperature on the dies sufficient to cause them to release from the clay without appreciably crazing the clay, and individually regulable valves associated with each burner for regulating the burner flame.

7. Pressing apparatus for shaping articles of clay comprising, a plurality of die members, a support member for receiving molds carrying a charge of clay, means for moving the die members and support member relative to one another to spread clay over the molding surface of the molds, means for stripping the molds from the dies, a fuel burner associated with each die, a fuel supply line common to all of the burners, a valve for varying the flow of fuel through the line to the several burners, periodically, automatically operated means for actuating the valve to increase and decrease the supply of fuel fed to all of the burners to maintain an operating temperature on the dies sufiicient to cause them to release from the clay without appreciably crazing the clay, an igniter associated with each burner, and periodically, automatically operated means for operating said igniters.

8. Pressing apparatus for shaping articles of clay comprising, a plurality of die members, a support member for receiving molds carrying a charge of clay, means for moving the die members and support member relative to one another to spread clay over the molding surface of the molds, means for stripping the molds from the dies, a fuel burner associated with each die, a fuel supply line common to all of the burners, a valve for varying the flow of fuel through the line to the several burners, periodically, automatically operated means for actuating the valve to increase and decrease the supply of fuel fed to all of the burners to maintain an Operating temperature on the dies suflicient to cause them to release from the clay without appreciably crazing the clay, individually regulable valves associated with each burner for regulating the burner flame, and a pilot burner assoelated with each burner.

9. In apparatus for fabricating potteryware, a lintel having a plurality of chambered forming dies detachably mounted thereon in spaced relation, a movable crosshead therebelow having a plurality of mold receiving and supporting chucks mounted thereon in spaced relation and in register with dies thereabove, means for raising and lowering said crosshead to elevate molds to a forming position adjacent said dies, and means for heating said dies including a burner in each of said die chambers, a fuel line extending across the lintel and being connected by individual branch pipes with the combustion chamber in each die, and a valve in each branch pipe for regulating the flow of combustible fluid toeach die.

10. In apparatus for fabricating potteryware, ,a hollow lintel, a plurality of forming dies detachably suspended from said lintel, a movable crosshead therebelow having a plurality of mold chucks mounted thereon in spaced relation, means for raising and lowering said crosshead to elevate molds to a forming position adjacent said dies, and means for heating said dies including a fuel burner disposed in each die, a fuel pipe inside the hollow lintel, branch pipes connecting said fuel pipes with each of said dies, and a valve in each branch pipe for individually regulating the flow of fuel to each die.

WILLIAM J. MILLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 819,517 Clark May 1, 1906 1,696,840 Dickinson Dec. 25, 1928 2,285,704 Frank June 9, 1942 2,298,223 Miller Oct. 6, 1942 2,310,068 Emerson Feb. 2, 1943 FOREIGN PATENTS Number Country Date 229,381 Great Britain Feb. 19, 1925 

